Will Americans Love Glasgow Celtic?

Europe's most famous soccer teams are having a busy summer wooing fans in that perennial soccer wasteland, the U.S. Scottish champion Glasgow Celtic, English powerhouses Manchester United and Chelsea, and Italian champ AC Milan are among nine teams on tour, playing in such cities as Seattle, Cleveland and Philadelphia, often to packed stadiums.

For the players it's a chance for a preseason tune-up in a perfect environment--away from their rabid fans. "The facilities are second to none," says Chelsea Football Club CEO Peter Kenyon. But, more important, the big clubs see the U.S. as a vital market in the race to...